Root-Microbe Interactions: The Importance of Protein Secretion

Clelia      De-la-Pena; Jorge      M. Vivanco

Abstract

The interactions between plants and microbes have been widely studied using gene expression studies and small molecule exchange between organisms. For the most part, these studies have focused on aboveground interactions and fewer studies have examined these types of processes belowground. The purpose of this review is to summarize the current literature looking at the interactions between roots and soil microbes, with an emphasis on the exchange of proteins between the organisms. Roots can establish close contact with different microorganisms in the rhizosphere, from pathogens to beneficial bacteria such as nitrogen fixers; recent data indicate that protein exchange is an integral part of these associations. These interactions include the release by roots of defense proteins, proteins involved in bacterial chemotaxis and proteins found inside root border cells, and release of proteins from bacteria that could activate innate immunity in plants. The overall goal of this review is to convey recent proteomic information related to root-microbe exchange to identify potential areas of development to improve agriculture.

Keywords: Proteomics, root exudates, nodulation, pathogenesis, symbiosis, defense, interaction, microbes, rooteomics, Glomus mosseae, Erwinia chrysanthemi, pectate lyases, quorum-sensing, N-acyl-homoserine lactones, Pseudomonas aeruginosa, Trichoderma harzianum, Fusarium graminearum, Phytophthora ramorus, Sclerotinia sclerotiorum, Aphanomyces euteiches, Glomus versiforme, Sinorhizobium meliloti, Brassica napus